Diagnostic evaluation of patients with blunt abdominal trauma: A decision analysis

Objectives: Using decision analysis, to compare the expected utility (EU) o f diagnostic peritoneal lavage (DPL), computed tomography (CT), and ultraso nography (US) to determine the optimal modality for the evaluation of blunt abdominal trauma (BAT) in hemodynamically stable adults. Methods: Data poi nts for the decision analysis were obtained from three sources: 1) prevalen ce of BAT and the sensitivity and specificity of each diagnostic modality w ere determined through a criteria-based review of the literature; 2) rate o f BAT necessitating immediate intervention, perioperative complication rate , and operative mortality rate were calculated using data from the authors' institution's trauma registry; and 3) outcome utilities were determined la y telephone survey of adults in a random sample of households in the region . The decision tree was constructed and evaluated in standard fashion. For each diagnostic modality, the authors calculated the EU using the minimum, mean, and maximum sensitivity and specificity across a range of prevalence. Mean outcome utilities were used for each branch of the tree when calculat ing the EU. Results: The EU of CT was consistently lower than the EUs of DP L and US at all levels of prevalence. However, the rank order of the EUs of US and DPL varied with the prevalence of BAT. When the prevalence was <30% , the EU of US was higher than that for DPL. When the prevalence was 30-40% , the EUs were similar. When the prevalence was >40%, the EU of US was less than that of DPL. Conclusions: Among institutions operating under constrai nts similar to those used in this model, the optimal diagnostic modality fo r the evaluation of BAT can be determined based on the sensitivity and spec ificity of the modality at their institution and the prevalence of BAT in t heir patient population.